American researchers have developed an approach that allows the use of compact antineutrino detectors to detect the illegal production of even very small amounts of plutonium and other heavy isotopes in future thermonuclear reactors.
elchi reports that, according to physicists in an article in the scientific journal “Physical Review Applied,” this will allow for increasing the nuclear security of these facilities.
The study notes: “Thermonuclear reactors will be the foundation of the carbon-free energy of the future, but it is theoretically possible to use these systems for the production of weapons-grade fissile materials. We have shown that such illegal use of these facilities can, in principle, be detected with the help of even a small antineutrino detector.”
The authors of this idea — a group of physicists led by Professor Patrick Huber of Virginia Tech in the US — note that thermonuclear reactors are currently considered a safer alternative to conventional nuclear reactors in terms of nuclear non-proliferation. However, they generate powerful neutron fluxes, which themselves could be used to convert uranium-238 and thorium-232 into other elements that could potentially be used in weapons.
Specifically, theoretically, uranium or thorium particles or compounds could be surreptitiously added to the cooling systems of these thermonuclear reactors. This would allow “malicious actors” to obtain tens of kilograms of plutonium or uranium-233 suitable for use in nuclear and thermonuclear warheads in just one week. These considerations prompted Professor Huber and other scientists to study in detail how these illegal radionuclides might “give themselves away.”
Guided by this idea, the scientists calculated how the neutron flux generated by a small 1.5 GW thermonuclear reactor would affect uranium-238 atoms within the coolant liquids, such as lithium and lead alloys or fluoride, lithium, and beryllium salts, which are planned for use in such facilities. These calculations showed that in both cases, the interaction between neutrons and uranium-238 and other radionuclides would create a large number of antineutrinos with a unique energy spectrum structure.
Professor Huber and other scientists found that it is possible to distinguish and capture these particles from antineutrinos generated by natural processes and those entering Earth from space. Even when the scale of plutonium production is relatively small, this can be done using a compact antineutrino detector weighing only one ton. The physicists concluded that such devices would help ensure the nuclear security of clean and reliable energy sources.
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